1. Field of the Invention
The present invention relates to an apparatus for testing electronic circuits, such as semiconductor circuits, and a testing method using the apparatus.
2. Description of the Related Art
FIG. 2 illustrates construction of a conventional electronic circuit testing apparatus. Voltage and current sources 1 (referred to as "power sources" hereinafter) apply voltages or currents to a testee circuit 4 and detect the currents or voltages which occur in the testee circuit 4. Thus, the power sources 1 have the function of testers. The testee circuit 4 is an electronic circuit, such as a semiconductor device (an IC package, etc.), and has terminals a to f. The power sources 1 are connected to a switching circuit 3 by their respective on-off switches 2. The testee circuit 4 is placed on a testing peripheral circuit 5. Lines from the power sources 1 and lines from input-output terminals 5a of the testing peripheral circuit 5 are wired in a matrix arrangement on the switching circuit 3. Many select switches 3a are arranged in the matrix and connect the lines from the power sources 1 to the lines from the input-output terminals 5a. The power sources 1 can be connected to desired input-output terminals 1 by operating selected switches 3a. The testing peripheral circuit 5 tests the testee circuit 4 and comprises resistors, capacitors, etc. (not shown), which are required for the test. The input-output terminals 5a are connected to the predetermined terminals a to f of the testee circuit 4. A control unit 6 is composed of, for example, a personal computer. According to a test control program 10 thereof, the control unit 6 controls voltage or current levels of the power sources 1 and the operation of the on-off switches 2 of the power sources 1 and the select switches 3a of the switching circuit 3.
Operation of the electronic circuit testing apparatus will now be described. The control unit 6 designates test conditions, for example, the level of supplied voltage if current is to be detected or the level of supplied current if voltage is to be detected. The power sources 1 supply voltage or current of the designated levels to a testee circuit 4 through the on-off switches 2, switching circuit 3 and the testing peripheral circuit 5. The on-off switches 2 and the select switches 3a of the switching circuit 3 are operated so that the designated levels of voltage or current are supplied to desired terminals a to f of the testee circuit 4 and that the levels of current or voltage at the desired terminals a to f are detected.
In a conventional electronic circuit testing apparatus constructed as above, the power sources 1 supply current or voltage to and detect voltage or current from the input-output terminals of the testing peripheral circuit which are selected solely by operation of the on-off switches and the select switches of the switching circuit. Therefore, it is troublesome to change the connections between the terminals of a testee circuit and the input-output terminals of the testing peripheral circuit. The test control program must be rewritten, or the hardware connections between the input-output terminals and the testee circuit must be changed. Also, the test control program or the testing peripheral circuit must be changed to test electronic circuits which have different connections to the input-output terminals even though the electronic circuits have the same function.